A PowerShell script that identifies the interface with the default Internet route, sets it to the highest priority, and verifies connectivity by pinging Google.

RouteOptima.ps1

# Identify the interface with the default route to the Internet (0.0.0.0 route)
$defaultRoute = Get-NetRoute -DestinationPrefix "0.0.0.0/0" | Sort-Object -Property RouteMetric | Select-Object -First 1
$interfaceIndex = $defaultRoute.InterfaceIndex

# Retrieve all network interfaces
$interfaces = Get-NetIPInterface -AddressFamily IPv4

# Set the priority for the interface with the default route to the highest (lowest metric)
foreach ($interface in $interfaces) {
    if ($interface.InterfaceIndex -eq $interfaceIndex) {
        Set-NetIPInterface -InterfaceIndex $interface.InterfaceIndex -InterfaceMetric 1
    } else {
        # Optional: Increase the metric for other interfaces to deprioritize them
        Set-NetIPInterface -InterfaceIndex $interface.InterfaceIndex -InterfaceMetric ($interface.InterfaceMetric + 1)
    }
}

# Test connectivity to Google's public DNS to confirm the interface has a route to the Internet
$testResult = Test-Connection -ComputerName "google.com" -Count 1 -ErrorAction SilentlyContinue

if ($testResult) {
    Write-Output "Successfully pinged Google. Internet access is confirmed on interface with index: $interfaceIndex"
} else {
    Write-Output "Failed to ping Google. Check the Internet connection on interface with index: $interfaceIndex"
}